O. Arf, M. E. de Sá, C. S. Okita, M. A. Tiba, G. Guerreiro Neto, and F. Y. Ogassawara, “Effect of different spacing and densities of sowing on the development of beans (<i>Phaseolus vulgaris</i> L.)”, PAB, vol. 31, no. 9, pp. 629–634, Sep. 1996.